A datapoint type represents the data corresponding to a KNX device functionality. It describes the data, setting the rules about the format and values to be allowed, and it holds the bytes containing the data.
A datapoint type is identified by its main number and a sub number. Each main number corresponds to a datapoint type with a particular structure. The sub numbers correspond to different interpretations or naming of this structure.
The Qt KNX module provides a class for each datapoint type with the main number less than 30 and sub number less than 100. All datapoint types with the same main number inherit from a datapoint type class representing the main number datapoint type characteristics.
Datapoint types are used in the data part of the QKnxTpdu class, which is a part of a link layer frame ( QKnxLinkLayerFrame ) that is transmitted over a tunneling connection ( QKnxNetIpTunnel ).
QKnxDatapointType is the base class for all datapoint types. It is inherited by two main datapoint type classes: QKnxFixedSizeDatapointType for fixed length datapoint types and QKnxVariableSizeDatapointType for variable length datapoint types.
QKnxDatapointType::Type lists the datapoint types that have been implemented in the Qt KNX module with short descriptions and their main and sub numbers. Datapoint types described in the KNX documentation can be added by creating a class that inherits from QKnxFixedSizeDatapointType or QKnxVariableSizeDatapointType and registering this new class using an instance of QKnxDatapointTypeFactory .
The QKnxDatapointTypeFactory class is used to create datapoint types based on their main number and sub number. One or more datapoints can be registered with the factory and then queried based on the main number and sub number.
The following diagram shows the base Qt KNX module datapoint type classes and the classes derived from them for the main datapoint types:
| Abstract base class for datapoint types that contain time information | |
| Boolean datapoint type, such as switch on or off | |
| Boolean datapoint type with a control part | |
| Fixed size datapoint type with the length of 1 byte | |
| Fixed size datapoint type with the length of 2 bits | |
| Datapoint type for a 2-byte float value | |
| Datapoint type with a 2-byte signed value | |
| Datapoint type with a 2-byte unsigned value | |
| Datapoint type with the 32-bit set | |
| Datapoint type with a control part | |
| Datapoint type for a 4-byte float value | |
| Datapoint type with a 4-byte unsigned value | |
| Datapoint type with binary-coded values in all fields | |
| Datapoint type with an 8-bit signed value | |
| Datapoint type with an 8-bit unsigned value | |
| Datapoint type for storing the actuator connection type | |
| Datapoint type for storing the alarm class type | |
| Fixed size datapoint type for storing the alarm reaction | |
| Datapoint type for storing the application area | |
| Datapoint type for storing the Beaufort wind force scale | |
| Datapoint type for storing the building mode | |
| Datapoint type that encodes a character | |
| Datapoint type that encodes an ISO 8859-1 character | |
| Datapoint type that encodes an ASCII character | |
| Datapoint type that encodes a string | |
| Datapoint type that encodes a string of ISO 8859-1 characters | |
| Datapoint type that encodes a string of ASCII characters | |
| Datapoint type for storing the scale of the sky obscured by clouds when observed from a particular location | |
| Datapoint type for storing combined information about the on and off states of a multiple-channel binary actuator | |
| Datapoint type for controlling blinds | |
| Datapoint type for controlling dimming | |
| Base class for datapoint types with specific properties | |
| Used to create QKnxDatapointType objects based on their main number and sub number | |
| Datapoint type for a date | |
| Datapoint type for the date and time | |
| Datapoint type for device control | |
| Datapoint type for electrical energy | |
| Datapoint type for controlling entrance access | |
| Datapoint type for storing errors in heating, ventilation, and air conditioning (HVAC) | |
| Datapoint type for storing system errors | |
| Base class for datapoint types with a fixed size | |
| Datapoint type for general status | |
| Datapoint type for storing the light application mode | |
| Datapoint type for storing the occupy mode | |
| Fixed size datapoint type for storing the on/off action | |
| Datapoint type for storing priority | |
| Datapoint type for storing the bus power supply unit mode | |
| Datapoint type for a scene control | |
| Datapoint type for scene information | |
| Datapoint type for a scene number | |
| Datapoint type for storing the system clock (SCLO) mode | |
| Datapoint type for storing the sensor mode | |
| Datapoint type for a status mode 3 | |
| Holds time information | |
| Holds time information | |
| Base class for datapoint types that contain time information | |
| Datapoint type for storing a time delay | |
| Datapoint type for the time of day | |
| QKnxOnOffAction class is a fixed size datapoint type for storing the up/down action | |
| Datapoint type for a UTF-8 string | |
| Datapoint type for a UTF-8 string | |
| Datapoint type with a 4-byte unsigned value | |
| Datapoint type that encodes a variable length string | |
| Datapoint type that encodes a variable length string of ISO 8859-1 characters | |
| Base class for datapoint types with a variable size |
